Referring to FIGS. 1 and 2, in co-pending U.S. patent application Ser. No. 09/407,407, now U.S. Pat. No. 6,058,528, filled by the applicant, a playpen is shown to include a looped lower frame 13, a looped upper frame 12, a plurality of vertical posts 15, a cot 20 and a releasable fastening unit.
As illustrated, the upper frame 12 is disposed above and is spaced apart from the lower frame 13 in a vertical direction. The vertical posts 15 bridge the upper and lower frames 12,13.
The cot 20 has a bottom wall 21 made from a cushioning material and a surrounding wall 22 formed from a fabric material. The surrounding wall 22 is connected to a periphery of the bottom wall 21 and extends upwardly from the bottom wall 21. The surrounding wall 22 has a length in the vertical direction which is shorter than a distance between the upper and lower frames 12,13 in the vertical direction. The surrounding wall 22 further has a distal top portion 220 that engages the upper frame 12 for suspending the cot 20 thereon, as best shown in FIG. 1, such that the bottom wall 21 is disposed above the lower frame 13. The distal top portion 220 of the surrounding wall 22 further has an outwardly folded section 222 defining a looped receiving groove 223 that opens downward for receiving removably the upper frame 12 therein. The outwardly folded section 222 is provided with a plurality of notches 221 that are registered with the vertical posts 15, respectively.
The releasable fastener unit includes a plurality of complementary male and female fastener sets 23,16. The female fastener sets 16 are secured to the vertical posts 15, while the male fastener sets 23 are secured to the outwardly folded section 222 and extend into the notches 221 such that each fastener 160 of the female fastener sets 16 is disposed between a pair of fasteners 230 of the male fastener sets 23. Each of the fasteners 230, 160 of the male and female fastener sets (23,16) is formed with a coupling ring (233,165). Each of the vertical posts 15 is provided with an anchoring strap 167 that is connected to the coupling ring 165 of a respective one of the fasteners 160 of the female fastener sets 16. Each of the fasteners 160 of the female fastener sets 16 includes a hollow fastener body 161 with two opposite open insert ends 162, and a confining wall 163 that is formed with opposite engaging slots 164. Each of the fasteners 230 of the male fastener sets 23 has an insert portion 232 that is extended into the hollow fastener body 161 of a corresponding one of the fasteners 160 of the female fastener sets 16 via the open insert end 162 and that is formed with resilient projections 2321 for engaging releasably the engaging slots 164 in the hollow fastener body 161 of the corresponding one of the fasteners 160 of the female fastener sets 16.
Some of the drawbacks that result from the use of the aforesaid playpen are as follows:
(i) The resilient projections 2321 in each of the fasteners 230 are pressed by the user toward each other in order to remove the same from the engaging slots 164 of the fastener 160, which subsequently, can cause pain to the user's fingers.
(ii) The fasteners 160 are fastened to an enclosure 11 via the coupling ring 165 and the anchoring straps 167. It is noted that the enclosure 11 may easily tear due to the weight of the baby disposed in the cot 20. Thus, the service life of the aforesaid playpen is relatively short.